diff --git a/config.h b/config.h
index 7805e07..8a4be0b 100644
--- a/config.h
+++ b/config.h
@@ -4,3 +4,7 @@
 #ifndef PREFIX
 # define PREFIX "/usr/local"
 #endif
+
+#ifndef LIBDIR
+# define LIBDIR PREFIX "/lib"
+#endif